Rotator system including a remote drive motor and a local indicator-control motor

ABSTRACT

A rotator system is described wherein a remote drive motor rotates a shaft and an associated first cam. A regulated, local reversible motor when activated rotates a local indicator-control device and an associated second cam. The first and second cams function with separate switch means in a manner to each apply to the local motor one of two voltage potentials. The local reversible motor is responsive to a difference of electrical potential there across which is associated with the lack of synchronization of the two cams for causing rotation of the indicator-control device to correspond to the shaft rotation.

United States Patent [191 Smalser [111 3,831,074 Aug. 20, 1974 ROTATOR SYSTEM INCLUDING A REMOTE DRIVE MOTOR AND A LOCAL INDICATOR-CONTROL MOTOR [52] US. Cl 318/265, 318/673, 318/41 [51] Int. Cl. H02p 7/80 [58] Field of Search 318/41, 265-267,

[56] References Cited UNITED STATES PATENTS 2/1950 McNaney 318/673 8/1963 Dicke 318/41 lroler 318/265 X Primary Examiner-Robert K. Schaefer Assistant Examiner-W. E. Duncanson, Jr.

Attorney, Agent, or Firm-Edward J. Norton; Robert L. Troike [57] ABSTRACT A rotator system is described wherein a remote drive motor rotates a shaft and an associated first cam. A regulated, local reversible motor when activated rotates a local indicator-control device and an associated second cam. The first and second cams function with separate switch means in a manner to each apply to the local motor one of two voltage potentials. The local reversible motor is responsive to a difference of electrical potential there across which is associated with the lack of synchronization of the two cams for causing rotation of the indicator-control device to correspond to the shaft rotation.

8 Claims, 4 Drawing Figures I REVOLUTION SYNCHRONIZER 55 PATENIEUmszman NEH 1 Uv 2 3 5522525 zES SRE ROTATOR SYSTEM INCLUDING A REMOTE DRIVE MOTOR AND A LOCAL INDICATOR-CONTROL MOTOR This invention relates to a rotator system and particu larly to the use of a controlled reversible electric motor to drive an indicator-control device thatboth indicates position of a remote rotating shaft and automatically deactavates the system when at a preselected position.

In antenna rotators, for example, it is desirable to remotely preselect and to indicate the direction that an antenna is pointing. One way of achieving this is by means of a synchro system, i.e., a system of a generator and a motor where the rotor of a motor aligns itself with the fields of a stator winding. Such a synchro system is costly and therefore is generally considered as being undesirable asa rotator for home television antenna systems, FM receiving antennas, etc.

Another method of indicating antenna direction is by the pulsed energization of a solenoid which causes either the stepping of a ratchet wheel (see US. Pat. No. 3,501,969) or allows the movement of a spring driven escapement wheel one notch or tooth per movement of the solenoid. These ratcheting and escapement systems are noisy and sometimes require a pair of solenoids unless a specific structure is used to provide bidirectional movement. Further it is desirable to preselect the desired antenna direction and to use the same system for both indicating the pointing direction of the antenna and for automatically stopping the antenna at the preselected direction.

Briefly, according to the present invention, a rotator system is provided that includes anAC induction motor for driving the object to be rotated, a DC motor for driving an indicator and control member, and means for providing to one winding of the AC motor an AC supply voltage of one phase and to another winding of the AC motor an AC supply voltage of a second different phase to cause energization of the AC motor. A first terminal of the DC motor is coupled to either the first or the second winding of the AC motor depending upon the rotated position of the AC motor. The second terminal of the DC motor is coupled through an AC rectifier to either the first or the second windind depending upon the rotated position of the DC motor. The AC rectifier permits unidirectional rotation of the DC motor only when one terminal of the DC motor is coupled to the first winding and the opposite terminal of the DC motor is coupled to said second winding.

When both the first and second terminals of the DC.

motor are coupled to the same winding, the DC motor is deactivated.

DETAILED DESCRIPTION FIG. 4 is a perspective view of the direction-memory cam according to an embodiment of the present invention.

Referring to FIG. 1, a rotator system 10 includes a remote rotator drive unit 1 1, a local control unit 13 and four wires l5, 16, 17 and 19 interconnected between the control unit 13 and the remote drive unit 11. The control unit 13 may be located on top of a television set and the drive unit 11 may be loacated at a remote position such as at an antenna mast supported from and extending above the roof top of a dwelling.

Turning first to the remote drive unit 11, the drive unit includes a split-phase AC motor 31, a gear train 33, and a phase sensing system that includes a cam 45 and a multiposition contact switch 47. A rotatable shaft 35 to which an antenna mast (not shown) may be mounted is coupled to the gear train 33 which, in turn, is coupled to the AC motor 31. Upon rotation of the drive unit motor 31, the gear train 33 is activated and the shaft 35, the mast (not shown), and the cam 45 is rotated. The drive unit cam 45 in this example is geared to make one revolution for-every 6 of rotation by the drive unit shaft 35.

The drive unit AC motor 31 includes a pair of windings 31a and 31b. For operation of the AC motor, the power supply'is coupled to the windings 31a and 31b so as to provide a phase difference of the alternating potentials between the two windings. This can be accomplished by a phase shifting capacitor 37 coupled between wires 17 and 19 and by the arrangement of the windings. The windings 31a and 31b are coupled to a common point 32 at which wire 16 is connected. The

opposite end 34 of winding 31a is connected to wire 19. The opposite end 36 of winding 31b isconnected to wire 17. In the phase sensing system, the multiposition contact switch 47 has one terminal 48 coupled via wire 109 to wire 19 at end 34 of winding 31a and has a second terminal 46 coupled via wire 107 to wire 17 at end 36 of winding 31b. A center terminal 49 of multiposition switch 47 is coupled to wire 15. Wire is connected at one terminal 51a of a DC motor 51. This motor 51 and its operation is discussed in connection with the control unit 13. Terminal 49 is connected to contact 48a, and terminal 46 is connected to contact 46a of switch 47. Contact 49a is a movable contact member and is connected to tenninal member 49 of switch 47. Contact 49a is physically biased to be normally connected to contact 48a.

Cam 45 has a lobe 45a which, for example, in the present embodiment extends half way around the perimeter of the cam 45. As the cam 45 is rotated by the gear train 33, the lobe 45a of the cam drives the movable contact 49a into connection with contact 46a. When the lobe 45a has rotated out of touch with contact 49a, the contact 49a snaps back (due to the bias) into connection with contact 48a. When contact 490 makes connection with contact 46a, the AC voltage of a first phase at end 36 of winding 31b is coupled through switch 47 to wire 15. When contact 49a is out of contact with contact 46a and connects with contact 48a the AC voltage of a second phase at end 34 of winding 31a is coupled through switch 47 to wire 15.

Turning to the control unit 13, the provision of energizing potentials to the drive unit motor 31 is first described followed by a discussion of the manner in which a local indication and control of the rotation of the drive unit motor 31 is provided. At the control unit 13 input, a pair of terminals 14a and 14b couple 117 volts AC to the primary winding 23 of a'transformer 21. The transformer 21 steps down the voltage and provides 20 volts AC at the secondary winding 25. A main on-off switch 27 is coupled in series with the primary winding 23 of transformer 21. When the contacts 27a and 27b of switch 27 are closed, the 117 volts AC is applied across the primary coil 23 and coupled to the secondary winding 25 of transformer 21. If the contacts 27a and 27b are open, the transformer 21 and consequently the control unit 13 and the entire rotator system is de-energized.

The opening and closing of contacts 27a and 27b is provided by misalignment and alignment, respectively, of a preselector disk 54 (shown in more detail in FIGS. 2 and 3) and an indicator disk 53. For purposes of illustration, disks 53 and 54 shown in FIG. 1 in simplified form are tilted slightly so disk 54 can be seen. A more detailed discussion of this structure is provided below in connection with FIGS. 2 and 3. Briefly, however when a knob 81 is rotated clockwise or counterclockwise, the disk 54 that is coupled thereto is rotated clockwise or counterclockwise. Switch 27 which may be coupled to disk 54 turns with disk 54. The indicatorcontrol disk 53 is spaced parallel to and above disk 54 on a shaft'83 (see FIG. 3). Disk 53 is mounted so as to freely rotate on the shaft. Disk has an extension 84 thereon adapted so that when the disks 53 and 54 are aligned, extension 84 pushes contact 27a away from contact 27b, de-energizing the system When extension 84 is misaligned with switch 27, as when knob 81 rotates the disk 54 clockwise or counterclockwise, the contacts 27a and 27b are closed and the system is energized.

The volts AC at the secondary coil is applied through a motor direction switch 43 to the drive unit motOr 31 and to control unit motor 51. The end 25 1 of secondary 25 is coupled via wire 16 to a common point 32 of windings 31a and 31b of the drive unit motor 31. The end 25b of winding 25 is coupled to the center terminal 44 of switch 43. Terminal 41 of switch 43 is coupled by wire 19 to end point 34 of drive unit motor winding 31a. Terminal 42 is connected by wire 17 to end point 36 of drive unit motor winding 31b. The phase shifting capacitor 37 is coupled between wires 17 and 19 to provide a time-phased displacement between the currents in the two windings 31a and 31b and thereby facilitate activation of'the drive unit motor 31. Switch 43 is a flexible leaf contact switch with a flexible contact 44a connected to the terminal 44 and adapted to, when flexed, make contact with either contact member 420 connected to terminal 42 or with contact member 41a connected to terminal 41. The switch 43 is, for example, fixed to disk 54.

Also fixed to the disk 54 is a direction-memory c 87. The cam 87 is rotatably mounted to the disk 54 and has an extension that fits into a groove 89 in disk 53 when disks 53 and 54 are aligned. As shown in FIGS. 2 and 3, the cam 87 has gaps 102 and 104 therein. Flexible leaf contact 44a extends into gap 104. Wheb knob 81 rotates clockwise, the direction-memory cam 87 rotates counterclockwise and causes direction-memory cam 87 to push contact 44a into connection with contact 41a. When knob 81 rotates counterclockwise, the direction-memory cam rotates clockwise and causes contact 44a to connect with contact 42a. A

more detailed discussion of this cam 87 and the disks 53 and 54 is provided in connection with FIGS. 2 thru 4.

When contact 44a .makes connection with contact 41a, the drive unit motor 31 rotates clockwise, for example, with the current going through wires 19 and 16, winding 31a and contacts 44a and 41a. When contact member 44a is closed with contact member 42a, the drive unit motor 31 rotates in a counterclockwise direction with currents coupled through contact members 44a and 42a and along wires 17 and 16 and winding 31b.

At the control unit 13, a local indicatlon and control of the rotation of shaft and hence the pointing direction of the antenna is achieved by controlling the rotation of the indicator-control disk 53. The indicatorcontrol disk 53 is coupled by a gear train 52 to a DC control unit motor 51. Also coupled to gear train 52 is control unit cam 55. Control unit cam 55 has a lobe 55a which extends for the present example about half way around the perimeter of the control unit cam 55. Upon activation of the DC control unit motor 51, the gear train 52 is activated and the indicator-control disk 53 and the control unit cam 55 are rotated.

The control unit cam 55 is geared to make one revolution every 6 of turn by the indicator-control disk 53.

The same ratio of turns that exists between drive unit cam 45 and the antenna shaft 35 to 1) exists between the control unit cam 55 and indicator-control disk 53. The speed of DC control unit motor 51 is such that the control unit cam 55 turns faster than drive unit cam 45. Control unit cam 55 is driven sufficiently faster than drive unit cam 45 so that cam 55 turns one half of a complete revolution and indicator-control disk 53 progresses 3 before switch 47 can change connection of contacts and before shaft 35 and the antenna has rotated 3 The DC control unit motor 51 and hence the indicator-control disk 53 is caused to rotate in response to a difference in phase of alternating potentials between the tenninal ends 51a and 51b of motor 51. The consequential potential difference for activating the control unit motor 51 is dependent upon the lack of synchronization of cams 45 and 55. The terminal 51a is coupled via wire 15 to terminal 49 of switch 47. Since the contact 49a which is connected to terminal 49 makes connection with either contact 460 or contact 48a, the alternating voltage of the first phase at end 36 of winding 31b or the alternating voltage of a second phase at end 34 of winding 31a is coupled to terminal 51a of control unit motor 51. Since the phase of the voltage at terminal 49 of switch 47 and on wire 15 is dependent upon the position of cam 45, the rotated position of this cam 45 and consequently of the AC motor 31 is sensed by the phase of the alternating voltage at terminal 51 a of DC motor 51.

The terminal 51b of control unit motor 51 is coupled through either rectifier diode or 67, switch 61 to a terminal 72 of switch 71. Switch 61 determines which of the diodes 65 or 67 completes the circuit through the control unit motor 51 and consequently the direction of rotation of the control unit motor 51. Switch 71 has one terminal 73 coupled to wire 19 and to terminal 41 of switch 43. Terminal 74 of switch 71 is connected to wire 17 and to terminal 42 of switch 43. When contact 44a makes connection with contact 41a, the alternating potential of the second phase at end 2512 of secondary 25 and at wire 19 is coupled to terminal 73 of switch 71. When contact 44a makes connection with contact 42a, the alternating potential of the second phase at end 25b of secondary winding 25 and at wire 17 is coupled to terminal 74 of switch 71. The center terminal 72 of switch 71 is coupled via wire 69 to terminal 66 of switch 61, and dependent upon the position of switch 61 either diode 65 or 67 completes the circuit to terminal 51b of DC motor 51. The center terminal 72 of switch 71 is connected to a movable contact 72a.

The control unit cam 55 drives the movable contact 72a such that only the lobe 55a forces the movable contact 72a into connection with contact 74a. When the control unit cam 55 is rotated so that lobe 55a is no longer in contact with movable contact 72a, the contact 72, which is biased so that it is normally closed with contact 73a, snaps into connection with contact 73a. As the control unit motor 51 rotates, cam 55 is rotated, the alternating voltage of the phase at wire 17 and of the phase at wire 19 is rectified and alternately coupled to terminal 51b of the DC control unit motor 51.

Since switch terminal 46 of switch 47 and switch terminal 74 of switch 71 are both connectable via wires 107 and 101 respectively to wire 17 and to terminal 42, the alternating potentials and the phase of these potentials at contacts 46a and 74a are approximately the same. When the cams 45 and 55 are in the synchronized position of FIG. 1, so that movable contact 49a makes connection with contact 46a and movable contact 72a makes connection with contact 74a, the terminals 51a and 51b of DC control unit motor 51 are coupled to the same alternating potential value and phase. Motor 51 remains inactivated.

Similarly, since switch terminal 48 of switch 47 and switch terminal 73 of switch 71 are both connected via wires 109 and 103 respectively to wire 19 and terminal 41, the alternating potential value and phase at contacts 48a and 73a are approximately the same. When both cams 45 and 55 are synchronized so that both movable contacts 49a and 72a are off the lobes 45a and 55a, contacts 49a and 48a are connected and contacts 72a and 73a are connected causing again a like alternating potential value and phase to terminals 51a and 5 lb of the control unit motor. It can therefore be perceived that when the cams 45 and 55 are synchronized the motor 51 is deactivated.

If, however, these cams are out of synchronization, as when the drive unit motor 31 rotates cam 45, a difference of potential across the DC motor 51 exists. This difference of potential is caused, for example, by the switch 47 making connection to wire 19 and the switch 71 making connection to wire 17. Also this difference of potential is caused by switch 47 making connection to wire 17 and switch 71 making connection to wire 19. As mentioned previously, the voltage at wire 19 is out of phase with the voltage at wire 17 since wire 17 is coupled to winding 31b and wire 19 is coupled to oppositely phased winding 31a and since these wires are coupled to the opposite terminal ends of phases shifting capacitor 37. When the voltages at the terminals 51a and 51b are out of phase, a difference of potential exists across the motor. With the addition of a rectifier, such as either diode 65 or 67, in the DC control motor circuit, only selected unidirectional rotation of the motor occurs.

The direction in which the DC control unit motor 51 turns is determined by the position of switch 61. The switch 61 is fixed, for example, to disk 54 with the center contact member 66a positioned in gap 102 of the direction-memory cam 87. A terminal 68 of switch 61 is coupled to the anode 67a of diode 67. The cathode 67b of diode 67 is coupled to end 51b of DC control unit motor 51. Terminal 64 of switch 61 is coupled to the cathode 65b of diode 65. The anode 65a of'diode 65 is coupled to the end 51b of DC motor 51. Diodes 65 and 67 each provide half wave rectifiecation of the 20 volt AC from the secondary coil 25 via switches 61, 71, and 43. The 20 volt AC is coupled to either diode 65 or 67 depending upon the position of switch 61.

The center leaf contact member 66a can make contact with either contacts 68a or 640. Contact 68a is connected to terminal 68, and contact member 64a is connected to terminal 64. The flexible contact member 66a is connected to terminal 66 of switch'61 which in turn is coupled by wire 69 to terminal 72 of switch 71. When switch member 61 is in the closed position whereby center flexible leaf contact member 66a makes contact with member 64a, the 20 volt AC is coupled through switch 71 and wire 69 to diode 65. Diode 65 then completes the circuit to terminal 51b. of DC motor 51. When the out-of-phase potentials are applied across the series combination of the DC motor 51 and the diode 65, the DC motor is allowed to rotate in only one direction due to the rectification by the diode 65. When flexible contact member 66a makes contact with member 68a, as when the direction-memory cam 87 rotates clockwise, the 20 volts AC is coupled through switch 71 and wire 69 to diode 67. Diode 67 then completes the circuit to terminal 51b of the DC motor 51. Due to the rectification by the diode 67, the DC motor 51 is permitted to rotate only in a direction opposite the above one direction.

The operation of the above described rotator system 10 as shown in FIG. 1 follows. When the control knob 81 is rotated clockwise rotating preselector disk 54 clockwise, direction-memory cam 87 is rotated counterclockwise, contact member 44a contacts member 41a of switch 43 and contact members 64a and 66a of switch 61 are connected. Also, due to the rotation of preselector disk 54 relative to indicator-control disk 53, contacts 27a and 27b are closed energizing secondary 25. The alternating potential of the second phase from terminal 25b of secondary 25 is coupled via wire 19 and contacts 41a and 44a across winding 31a of drive unit motor 31, thereby causing it to rotate clockwise. The alternating potential of the second phase at terminal 25b is coupled to terminal 48 of switch 47. when the lobe a is in the position shown in FIG. 1, the center contact member 49a is making connection with member 46a.

In the local control unit 13, when control knob 81 rotates clockwise and rotates clockwise preselector disk 54, contacts 27a and 27b are misaligned energizing secondary 25. Also, when the preselector disk 54 is rotated clockwise, the direction-memory cam 87 is caused to rotate counterclockwise and contacts 44a and 41a of switch 43 are connected and contacts 64a and 66a of switch 61 are connected. When contacts 44a and 41a are connected, the alternating potential of the second phase at terminal 25b is applied to end 34 of winding 31a via wire 19 and to terminal 73 of switch 71 via wire 103. An AC voltage of the first phase is provided at end 36 of winding 31b and at terminal 74 of switch 71. When contacts 64a and 66a are connected, diode 65 is placed in the DC motor circuit allowing the control unit motor 51 to rotate only in a clockwise direction and toward realignment of disks 53 and 54. When the lobe 45a is in the position shown in FIG. 1, the center contact 49a is connected to contact 46a. The contact 46a is connected via wire 107 to wire 17. The alternating potential of the first phase at wire 17, which is out of phase with that at wire 19, is then applied to terminal end 51a. When the lobe 55a is in the position shown in FIG. 1, the center contact 72a is connected to contact 74a and contact 74a is connected via wire 101 to wire 17. The alternating potential of the first phase at wire 17 is then applied via switch 71 and switch 61'to diode 65. Since the opposite end of diode 65 is connected to terminal end 51b of DC motor 51 and consequently both ends of the series combination of diode 65 and control unit motor 51 are coupled to the same alternating potential of the same phase at wire 17, the circuit is balanced and the DC control unit motor 51 is deactivated.

After the AC motor 31 has rotated sufficiently clockwise because of the voltage across winding 31a so that the lobe 45a no longer pushes contact 49a, contact 49a makes connection with contact 48a. The sensed alternating potential of the second phase at point 34 of winding 31a is coupled through switch 47 and wire to terminal 51a of DC motor 51. Since switch 71 is still completing the connection of the alternating potential of the first phase at wire 17 to terminal 51b, there exists a phase different and consequently a voltage difference across the series combination of the DC motor 51 and diode 65 and the DC motor 51 rotates and drives cam 55 and indicator-control disk 53. The DC motor 51 direction is controlled by diode 65. The DC motor 51 continues to drive the cam 55 and the indicator-control disk 53 until cam 55 is rotated so that contact 720 is off the lobe 55a and snaps into connection with contact 73a. Contact terminal 73 is connected via wire 103 to wire 19 and via switch 43 to the alternating potential of the second phase at end b of secondary 25. Since this same potential is coupled via switch 47 to terminal end 51a of the DC motor 51, the motor is deactivated.

When the cam is driven by the drive unit motor 31 so that contact 49a again makes connection with contact 46a, the alternating potential of the first phase at wire 17 and at end 36 of winding 31b is coupled through switch 47 and wire 15 to terminal 51a of DC motor 51. Since switch 71 is making connection to the alternating potential of the second phase at wire 19, the DC motor 51 is energized, causing rotation of cam toward alignment. Because only diode is switched into the DC control motor 51 circuit, current during a difference in the phase of the potentials can flow in only one direction through the DC control motor 51 causing single directional rotation of that motor.

When the DC control unit motor 51 rotates the control unit cam 55 and drives the indicator-control disk 53 to a point where the lobe 55a drives contact member 720 into contact with contact 74a as shown in FIG. 1, the alternating potential of the first phase at wire 17 is then coupled to the series combination of diode 65 and the DC control unit motor 51 and it is deactivated. The above operation repeats itself until the indicator disk 53 aligns itself with the selector disk 54 and the system is de-energized by the opening of switch 27. The resynchronization of the DC motor 51 by energizing the DC motor 51, rotating the cam 55 one half revolution and shutting off the motor when a balanced potential occurs across the control unit motor continues for each change in position of switch 47 and corresponding reversing phase signal at the drive unit 11 until the selected position is reached, wherein the drive unti 11 is de-energized and the main on-off switch 27 is in the off or open position. This resynchronization at half revolution intervals of the cams 45 and 55 ensures that the aritenna or remote rotator is kept in alignment with the control unit despite variations in the drive motor 31 speed due to variable loading on the antenna drive motor 31.

When the control knob 81 is rotated counterclockwise so as to rotate direction-memory cam 87 clockwise, contact 44a, of switch- 43 makes contact with contact 42a and contacts 66a and 68a are connected. Also contacts 27a and 27b are misaligned. When contacts 420 and 44a are connected, the alternating voltage of the second phase at terminal 25b is now applied to terminal 36 of winding 31b via wire 17 and to terminal 74 of switch 71 via wire 101. When contacts 64a and 660 connected, diode 67 is placed in the DC motor 51 circuit allowingthe motor to rotate in only a counterclockwise direction to realign the disks 53 and 54.

When lobe 45a is in the position shown in FIG. 1, the center contact 490 is making connection with contact member 46a. Consequently, wire 15 is coupled to wire 17 which is at the alternating potential of the phase at end 25b of secondary 25. When lobe 55a is in the position shown in FIG. 1, center contact 72a of switch 71 makes connection with contact 74a. Contact member 74a is also connected to wire 17 via wire 101 and to terminal 42 and therefore the 20 volts AC of the same phase as at wire 15 and no potential difference is across DC motor 51.

Since the contacts 44a and 42a are connected, 20 volts AC is coupled across winding 31b of AC motor 31 to wire 16 and the drive unit motor 31 and cam 45 rotate counterclockwise. When cam 45 is driven so that lobe 45a moves away from contact arm 49a, contact 49a makes connection with contact 48a and the voltage of the first phase at winding 31a and at wire 19 is applied through switch 47 and wire 15 to terminal 51a of DC motor 51. Since switch 71 is still completing the connection of the voltage of the second phase at winding 31b and wire 17 to terminal 51b, the DC motor senses a voltage differential in one sense through diode 67 and rotates counterclockwise, driving cam 55 and indicator disk 53 counterclockwise.

When the cam 55 is driven so that contact member 72a is off the lobe 55a, the switch 71 changes state and contact 72a connects with contact 73a. Contact 73a is connected to the voltage of the first phase at wire 19 and winding 31a and the voltage across the motor 51 is again equal and in phase and the DC control unit motor 51 is deactivated.

When the cam 45 is driven by continued rotation of drive unit motor 31 so that contact member 49a again makes contact with member 46a as shown in FIG. 1, the alternating voltage of the second phase at winding 31b and wire 17 is again coupled through switch 47 to terminal 51a. Since the contact 72a is connected to contact 73a and to wire 19 and winding 31a difference in the phase of the potentials exists across the series combination of DC motor 51 and diode 67 causing activation of the motor and causing rotation of cam 55 in a counterclockwise direction.

When cam 55 is again rotated back into the position of FIG. 1, namely so contacts 72a and 740 are connected, the voltage at wire 17 appears at the opposite end 51b of the series combination of diode 67 and control unit motor 51. Consequently, since both ends of the series combination of the diode 67 and DC control unit motor 51 are at the same potential and phase, the

control unit motor 51 is deactivated.

Referring to FlGS. 2 and 3, there is shown a top view and an elevation view respectively of the control unit 13 which includes an indicator-control disk 53 positioned in a given alignment above a selector disk 54. A control knob 81 is coupled to a shaft 83 which extends through indicator-control disk 53 and-is fixed to selector disk 54. Indicator-control disk 53 is mounted to shaft 83 so that it freely rotates about the shaft. Selector disk 54 is fixedly mounted and rotates with the shaft. The shaft 83 is fixed but rotatably mounted to a baseboard 85. Extending between selector disk 54 and indicator-control disk 53 is the leaf spring type, normally closed contact switch 27. A small member 84 extends from a point near the periphery of control disk-53 and only makes contact with normally closed on-off switch 27 when disks 53 and 54 are in aligned position therewith to break the contact between the members 27a and 27b, deactivating the system 10.

The motor direction switches 61 and 43 are mounted to selector disk 54. A rotatable direction-memory cam 87 is rotatably mounted to the selector disk 54 by a pin 88a having a head below disk 54 and extending through disk 54 and into base portion 95. Referring to FIG. 4, the direction-memory cam 87 includes a base portion 95 adapted to receive pin 88a and three parallel extending members 96, 97 and 98 spaced from each other and from the base portion 95 by a spacer portion 99. A tooth-shaped member 88 extends vertically and laterally from the base member 95. A gap 104 existsbetween members 98 and 97, and a gap 102 exists between members 97 and 96. The rotatable directionmemory cam 87 extends in the region between indicator-control disk 53 and selector disk 54 with the toothshaped extending member 88 positioned just below control disk 53. A ring member 53a positioned below indicator-control disk 53 may be formed as an extension of disk 53 to extend about the periphery of this disk 53. The ring member 53a has a groove 89 therein extending from the inboard surface. The tooth-shaped member 88 of direction-memory cam 87 is adapted to fit into groove 89 when the control disk 53 and selector disk 54 are aligned and the main on-off switch 27 is deenergized.

The direction-memory cam 87 and the switches are arranged so that flexible leaf member 44a extends through gap 104 and flexible leaf member 66a extends through gap 102. See FIGS. 2 and 4. When the control disk 53 and the selector disk 54 are aligned, the toothshaped member 88 is lodged into slot 89 and the flexible contact members 660 and 44a make no contact with either of their adjacent contact members. When the control knob 81 and disk 54 is rotated, for example, in a clockwise direction, the tooth-shaped member 88 is driven laterally and thereby rotates out of slot 89 and causes the direction-memory cam 87 to rotate, in the example, in a counterclockwise direction. When direction-memory cam 87 rotates in a counterclockwise direction, the member 98 of direction-memory cam 87 pushes contact member 44a and member 97 of direction-memory cam 87 pushes contact member 66a so that contact member 44a makes contact with member 41a and contact member 66a makes contact with member 64a. The drive unit 11 is then made to rotate in the selected direction with the DC control motor 51 made when energized to drive the control disk 53 in the proper direction to realign disk 53 with disk 54.

When the DC motor 51 drives disk 53 back to the aligned position with disk 54, the tooth-shaped member 88 is again in slot 89 of disk 53 centering the contact members 66a and 44a. When the control knob 81 is rotated in the opposite direction, counterclockwise, direction-memory cam 87 is rotated in a clockwise direction and with the member 44a making contact with member 42a and member 66a making contact with associated contact member 68a. The operation follows from the above description.

What is claimed is: l. A rotator comprising: an AC motor for driving the object to be rotated, said AC motor having a pair of windings,

potential coupling means for providing over one lead to one winding of the AC motor an AC potential of one phase and over a second lead to the second winding of the AC motor an AC potential of a second different phase to cause energization of said AC motor,

a two terminal DC motor for driving an indicator means,

means coupled between said first and second leads and a first terminal of said DC motor for providing at the first terminal of said DC motor an AC potential of said first phase when the AC motor is in one rotated position and an AC potential of the second phase when the AC motor is in a second rotated position,

means including an AC rectifier coupled between said first and second leads and the second terminal of said DC motor and responsive to the rotated position of said DC motor for causing activation of the DC motor when said first and second leads are coupled to opposite terminals of said DC motor and for causing de-energization of said DC motor when said first and second terminals of said DC motor are coupled to the same one of said leads.

2. The combination as claimed in claim 1, wherein said means coupled to said first terminal for providing an AC potential of either said first or second phase includes a switch having a first terminal connected to the first lead and a second terminal connected to the second lead and a third movable member of the switch coupled by a gear train to said AC motor.

3. The combination as claimed in claim 2, wherein said means coupled between said first and second leads and the second terminal of said DC motor includes a second switch having the center movable contact member coupled by a gear train to said DC motor.

4. The combination as claimed in claim 1, said potential coupling means including means for receiving the phase of the AC potential at said first and second leads to cause energization of said AC motor in an opposite sense.

5. The combinationas claimed in claim 4, wherein said means coupled between said first and second leads and the second terminal of said DC motor includes a pair of rectifiers with a first of the rectifiers allowing rotation of said DC motor in a first direction and the second rectifier permitting rotation of the DC motor in a second opposite direction.

6. A system for rotating a remote shaft and for providing a local indication of the rotated position thereof comprising:

a first reversible driving means including a reversible AC induction motor and a first gear train, said reversible AC motor having a pair of windings and responsive to energization potentials of one phase at one winding and of a second phase at the second winding for driving said remote shaft and gear train,

potential coupling means for providing over one lead to one winding of the AC motor an AC potential of one phase and over a second lead to another winding of the AC motor an AC potential of a second different phase to cause energization of said AC motor,

a local movable indicator,

a second driving means including a two terminal reversible DC motor and a second gear train coupled to each other and said indicator and responsive to an energizing potential applied thereto for driving said indicator,

a first switch means having a first contact coupled to a first winding of said AC motor and a second contact coupled to the second winding of said AC motor and a movable contact coupled to a first terminal of said DC motor, said movable contact being driven by said first gear train for in response to a given movement of said first gear train causing said movable contact to switch between said first and second contacts and consequently provide at the first terminal of said DC motor an AC potential of said first phase at one rotated position of the AC motor and an AC potential of said second phase at a second rotated position of the AC motor, a second switch means, an AC rectifying means coupled between said second switch means and the secondterminal of said DC motor for providing unidirectional potential across said DC motor, said second switch means having first contact member coupled to said first lead and a second contact member coupled to said second lead and. a movable contact member coupled to said rectifying means, said movable contact member being driven by said second gear train for in response to a given movement thereof causing said movable contact member to switch between said first and second contact members thereof and apply to said rectifying means and said DC motor said first and second phase potentials in a manner to cause energization of said DC motor when said gear trains are not synchronized so that said first and second leads are coupled to opposite. terminals of said DC motor and de-energization of said DC motor when said gear trains are synchronized so that said first and second terminals of said DC motor are coupled to the same one of said leads. 7. The combination as claimed in claim 6, wherein said first gear train includes a first cam which drives the movable contact of said first switch.

8. The combination as claimed in claim 6, wherein said second gear train includes a cam which drives the movable contact of said second switch. 

1. A rotator comprising: an AC motor for driving the object to be rotated, said AC motor having a pair of windings, potential coupling means for providing over one lead to one winding of the AC motor an AC potential of one phase and over a second lead to the second winding of the AC motor an AC potential of a second different phase to cause energization of said AC motor, a two terminal DC motor for driving an indicator means, means coupled between said first and second leads and a first terminal of said DC motor for providing at the first terminal of said DC motor an AC potential of said first phase when the AC motor is in one rotated position and an AC potential of the second phase when the AC motor is in a second rotated position, means including an AC rectifier coupled between said first and second leads and the second terminal of said DC motor and responsive to the rotated position of said DC motor for causing activation of the DC motor when said first and second leads are coupled to opposite terminals of said DC motor and for causing de-energization of said DC motor when said first and second terminals of said DC motor are coupled to the same one of said leads.
 2. The combination as claimed in claim 1, wherein said means coupled to said first terminal for providing an AC potential of either said first or second phase includes a switch having a first terminal connected to the first lead and a second terminal connected to the second lead and a third movable member of the switch coupled by a gear train to said AC motor.
 3. The combination as claimed in claim 2, wherein said means coupled between said first and second leads and the second terminal of said DC motor includes a second switch having the center movable contact member coupled by a gear train to said DC motor.
 4. The combination as claimed in claim 1, said potential coupling means including means for receiving the phase of the AC potential at said first and second leads to cause energization of said AC motor in an opposite sense.
 5. The combinationas claimed in claim 4, wherein said means coupled between said first and second leads and the second terminal of said DC motor includes a pair of rectifiers with a first of the rectifiers allowing rotation of said DC motor in a first direction and the second rectifier permitting rotation of the DC motor in a second opposite direction.
 6. A system for rotating a remote shaft and for providing a local indication of the rotated position thereof comprising: a first reversible driving means including a reversible AC induction motor and a first gear train, said reversible AC motor having a pair of windings and responsive to energization potentials of one phase at one winding and of a second phase at the second winding for driving said remote shaft and gear train, potential coupling means for providing over one lead to one winding of the AC motor an AC potential of one phase and over a second lead to another winding of the AC motor an AC potential of a second different phase to cause energization of said AC motor, a local movable indicator, a second driving means including a two terminal reversible DC motor and a second gear train coupled to each other and said indicator and responsive to an energizing potential applied thereto for driving said indicator, a first switch means having a first contact coupled to a first winding of said AC motor and a second contact coupled to the second winding of said AC motor and a movable contact coupled to a first terminal of said DC motor, said movable contact being driven by said first gear train for in response to a given movement of said first gear train causing said movable contact to switch between said first and second contacts and consequently provide at the first terminal of said DC motor an AC potential of said first phase at one rotated position of the AC motor and an AC potential of said second phase at a second rotated position of the AC motor, a second switch means, an AC rectifying means coupled between said second switch means and the second terminal of said DC motor for providing unidirectional potential across said DC motor, said second switch means having first contact member coupled to said first lead and a second contact member coupled to said second lead and a movable contact member coupled to said rectifying means, said movable contact member being driven by said second gear train for in response to a given movement thereof causing said movable contact member to switch between said first and second contact members thereof and apply to said rectifying means and said DC motor said first and second phase potentials in a manner to cause energization of said DC motor when said gear trains are not synchronized so that said first and second leads are coupled to opposite terminals of said DC motor and de-energization of said DC motor when said gear trains are synchronized so that said first and second terminals of said DC motor are coupled to the same one of said leads.
 7. The combination as claimed in claim 6, wherein said first gear train includes a first cam which drives the movable contact of said first switch.
 8. The combination as claimed in claim 6, wherein said second gear train includes a cam which drives the movable contact of said second switch. 